Electrical heating appliance.



No. 695,995. Patented Mar. 25, I902.

J. F. BACHMANN &. A. VOGT.

ELECTRICAL HEATING APPLIANCE.

(Application filed Nov. 22, 1898.) (No Model.)

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JOSEF FRANZ BACIIMANN LTD, OF LONDON, ENGLAND.

AND ADOLF VOGT, OF VIENNA, AllS'i. GARY, ASSIGNORS TO THE ELECTRIC RESISTANCE AND Ill ELECTRECAL HEATiNG APPLlANCEI.

I'PEQIFIGA ION formingpart of Letters Patent N0. 695,995, dated March 25, 196E Application filed November 22, 1898. Serial No. 697,191. (No model.)

i0 all 207mm 2 1'; may can/007%:

Be it known that "we, J OSEF FRANZ Beennavu and AnoLir Voc'r, subjects of the Einperor of Austria-Huugary,residin g at Vienna, 5 in the Province of Lower-Austria, in the Enipire of i'iustria-llungary, have invented certain new and useful Improvements in Electrical Heating Appliances; and we do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to ".rhich it appertaius to make and use the same, reference being had to the accompanying drawings, and to letters of reference marked thereon, which form a part of this specification.

This invention relates to electrical heating apparatus formed of artificial stone com pound produced in the manner described in our application, Serial. No. 654 560, dated October 8, 1897, by mixing together a conductor, such as carbon or metal, and a non-conductor, such as kaolin, with water or other liquid to form a paste, which after molding and drying is heated to a high degree While embedded in carbon powder or surrounded by reducing-gases.

The present invention relates to the applt cation of such artificial-stone compound as a heater for heating appliances, such as hollow soldering-irons, box-irons, and generally all such apparatus in which a hollow body is heated by an internal heating device forconveying heat through. the walls of the body to the outside thereof.

Figures 1, 2, and 8 of the acccolnpanying drawings show, by way of example, vertical sections of different forms of soldering-irons with our said invention applied thereto. Fig. a shows a vertical section of a box-iron heated internally by such electrical heater.

In the constructions shown at Figs. 1, 2, and 3 the hollow metal bodyf, constituting the soldering-iron, has inserted into it the heating-body a, made of the said artiiicialstone .5 compound, so that by the passage or an electric current through the body a this becomes heated in consequence of the resistance it offers to the passage of the current, such heat being transmitted through the walls of f to the outside thereol. The body a can be insulated from the soldering-iron fhy means of an insulating material or byair-insnlation or by a coating of glaze or enamel, or such insulation may be advantageously effected as follows: The body o is in the first instance made with a somewhatdess resistance than it is required to have when in use. .It is then provided with contacts and included in the circuit of an electric current, whereby it is heated to a high degree, such as to a white heat. By this means the conducting mate rial is burned out all over the enter surface of the body a, so that this is now left with an envelop of the remaining non-conductor, constituting an insulating-covering, but which is of a porous nature. This porous surface is then saturated or painted with an insulating substance in liquid form, which may consist either olt' a solution of the same non-con ductor that was used for the body a, such as clay or of a salt thereof, such as nitrate or sulfate of alumina, this operation being repeated, if necessary, so as to effectually till up the the pores of the said insulating-covering. If the body a to be glazed or enameled, this is effected in any well-known manner.

The point of the heater a which is in contact with the soldering-iron is preferably l vanized or made of metal for the better tr nsmission of the heat. The heater 0. can also be made with varying specific resistances its different parts in order to produce greatest development of heat at the point where it is more particularly required.

The one contact-wire Z) of the circuit is con nected to the heater by means of a screw, shown, while the second contact is formed the soldering-iron j, to which the circuit-lead is connected. In place of the second contact- Wire of the circuit a metal tube Z), Figs. 1 and 2, may be advantageously used as the conducter, passing through an insulated handle.

With apparatus of this kind it appears of advantage to enable the amount of electricity converted into heat to be regulated acccrd' to the degree of heat required altering t .e distance to be passed through by the currcu t.

Such an arrangement is shown at Fig. 3. In this case the contact-wires b, which pass from the circuit through the tubular handle g, are

connected to each end of the heating-body a,

as this is screwed more or less into a the resistance offered by the latter, and consequently the heat generated, will be decreased or increased. v

Fig. 4 shows a box-iron the body fof which has a hollow for the reception of the tubular heating-body a, the ends of which are provided with contacts, to which are connected insulated wires leading to terminal clamps c, to which the leads?) of an electric circuit are attached. The heater a is insulated from the box-iron f by an insulating-coating formed either on the heater or on the hollow of the box-iron. I

It will be evident that the above-described heaters of artificial-stone compound may be applied for supplying heat internally to various other apparatus requiring heat to be transmitted from their inner to their outer surfaces, such as heated stamping or branding dies, internally-heated rollers or cylinders for satin-presses, and the like. v

Having thus described the nature of this invention and the best means we know of carrying the same into practical effect, we claiml. Anelectricheatingappliance comprising a hollow body to be heated, an electric resistance therein com posed of a refractory non-cond uctive and a conductive material, the outer portionof said resistance being devoid of cond ucti ve material and porous, said pores closed by a refractory non-conductive substance to form a refractory electrically-insulating heattransmitting envelop for the resistance, and means for including the same in an electric circuit, for the purpose set forth.

2. An electrical heating apparatus for heating hollow bodies in the direction from within outward, consisting of an electric resistance composed of a mixture of conductive and nonconductive materials, said body being made of a form to fit the internal cavity of the body to be heated, with the interposition of an insulating-layer,a screw-threaded hollow in said heating-body, a screw-plug of conducting material screwed more or less into such hollow and contacts adapted to convey current from an electric circuit into said body through such conducting screw-plug and from the said body back to the circuit, for the purpose of varying the resistance offered by saidbody to the cura refractory non-conductive material and a conductive material, the outer portion of the resistance-body free from conductive material and porous and the pores closed by a refractory non-conductive substance to form'a refractory, electrically-insulating heat-trans. mitting envelop for said resistance body, means for including the same in an electric circuit and means for varying the resistance to the passage ,therethrough of the electriccurrent, for the purposes set forth.

4. An electric heating appliance comprising a hollow body to beheated, an electric resistance-body therein composed of a mixture of a refractory non-conductive material and a conductive material, the outer portion of the resistance-body free from conductive mate rial and porous and the pores closed by a refractory non-conductive substance to form a refractory, electrically insulating,heat-transmitting envelop" for said resistance body, means for including the same in an electric circuit and means for lengthening or shortening the path of the electric current therethrough, for the purposes set forth.

5. The combination with a hollow body to be heated, of an electric resistance-body therein made of refractory non-conductive and conductive materials, consisting substantially of an insulated outer portion and conductive inner portion, means for connecting opposite ends thereof to an electric circuit and a metallic screw arranged to be screwed into and out of said heater to vary the resistance therein, substantially as described.

6. The combination with ahollow body to be heated,of an internally-screw-threaded heater therein composed of electrically-conductive H and refractory nonconductive materials, a metallic ring at one end of said heater forming an electric terminal,,means for connecting a second electric terminal to the opposite end of said heater, and a metallic screw cooperating with the thread therein to vary the resistance, substantially as described.

7. Asoldering-iron comprisingahollow metallic body, an internallythreaded heater therein composed of electrically-00nductive and refractory non -c0nductive materials, a metallic point on the end of said heater contacting with the iron, metallic bands forming electric circuit terminals near each end of said heater, a plate closing the end of the soldering-iron and a screw organized to cooperate with the threaded portion of the heater and projecting beyond said plate, substantially as described.

In testimony that we claim the foregoing as our invention we hat e signed our names in presence of two subscribing witnesses.

' I J OSEF FRANZ BAOI'IMANN.

ADOLF VOGT. Witnesses:

ALVESTO S. HOGUE,

AUGUST FUGGER. 

